How and Why You Should Prune Tomato Plants (2024)

FAQs

How and Why You Should Prune Tomato Plants? ›

To speed ripening late in the season, remove the growing tip of each main stem about four weeks before the first expected fall frost. Called "topping," this type of pruning causes the plant to stop flowering and setting new fruit, and instead directs all sugars to the remaining fruit.

Prune for plant structure and health. Suckers form in the axils between the leaves and the main stem. Encourage a strong main stem by removing all suckers below the first flower cluster. A properly pruned and supported single-stem tomato plant presents all of its leaves to the sun.

If you leave the suckers on the plant, those suckers will turn into more vines. More vines mean more flower clusters and, eventually, more fruit. Each vine needs water and nutrients from the plant, so your plant won't have enough energy to spend on making each fruit really big. Overall, tomatoes will be smaller.

Cutting the tomato plants

The plants grow quite tall in summer and I often notice bunches of green tomatoes that I know won't ripen in time. That's when I cut the top off the tomato plants. This is a great way to keep the plant from growing even larger and instead ripening the fruits.

If you are keeping one leader, remove all suckers (new shoots that develop in the leaf axils). If you are keeping two leaders, save the sucker just below the first flower cluster. Remove all other suckers. Remove suckers when they are still small (less than 2 inches).

Rootstock tomatoes don't like getting pruned too much, as it will limit their growth and fruit bearing. This big, bushy, vigorous type of tomato likes to protect its fruit by setting it in the inner foliage. As the fruit are so small they can quickly burn & shrivel, I like to keep plenty of foliage around them.

Plants are usually ready to prune once they reach 12 to 18 inches in height. Photo by Julie Martens Forney. To do the Missouri pruning technique on suckers, pinch off the growing tip, leaving only the two lowest leaves.

Hi Merle, some people choose to trim the lower leaves of their tomato plants, others don't. The advantage in removing the lower leaves is that the plants energies go into producing fruit rather than a lot of foliage.

To grow the strongest tomato plant possible, prune side stems below the first fruit cluster. As a tomato plant matures, its lower leaves begin to yellow. Pinch or prune yellowed leaves to prevent disease, improve the tomato plant's appearance, and help the plant keep its energy focused on fruit production.

What happens if you don't pinch out tomatoes? ›

Now that you know how to pinch them out and also stop them, you can ensure most of the energy will go towards producing the trusses that in turn produce the fruit. Not doing this will mean you have a fantastically aromatic yet bushy plant that only produces tiny green unripe tomatoes by the end of the season.

If using a vertical string, gently wind the string around the top of the main stem once or twice a week as it grows. When plants reach the top of their support or have set seven fruit trusses indoors or four trusses outdoors, remove the growing point of the main stem at two leaves above the top truss.

If space in your garden is at a premium, or if you're supporting plants with tomato ladders or stakes, it's best to prune your tomato plants to one or two main stems. To do this, pinch out all suckers. Otherwise, suckers will grow into additional stems and create a wide, bushy plant.

Sunlight gives your tomato plants the energy to produce fruit, so if your plant doesn't have enough sunlight, you're less likely to see tomatoes fruiting. To increase sunlight, try: Moving your potted plant – If you have a potted tomato plant, try moving it to a sunnier location.

When the plant reaches the desired height–usually no taller than its support, 4 or 5 feet is good–consistently pinch out all new growing tips. In a week or so time, the plant will quit trying to put out new growth at the topmost part of the plant and concentrate on new growth and fruit below.

If an established, or larger plant becomes leggy, then they can often be saved by pruning them well and pinching the top off the plant. This encourages the plant to grow bushier and put its energy into something other than growing tall.